Belt of the heavens (6)
I believe the answer is:
zodiac
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">belt of the heavens</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for zodiac that I've seen before include "Astronogical sky band with 12 parts" , "Astrological belt" , "Horoscope diagram" , "Astrological band of the sky with 12 signs" , "Diagram of astrological signs" .)